In recent years, flat panel displays are used in a variety of commercial products and fields, and there is demand to further increase the size, improve the image quality, and reduce the power consumption of flat panel displays.
In these circumstances, organic EL display devices equipped with organic EL (electroluminescence) elements that use the electroluminescence (Electro Luminescence) of organic materials are recognized as all-solid-state flat panel displays that are excellent in terms of their low-voltage driving capability, fast responsiveness, self-luminous properties, and the like, and are attracting considerable attention.
Also, such organic EL display devices are used as display portions of electronic devices such as electronic books, personal computers, or tablets.
Moreover, for example, in an active-matrix organic EL display device, a thin film organic EL element is provided on a substrate on which a TFT (thin-film transistor) is provided. In the organic EL element, an organic EL layer including a light emitting layer is laminated between a pair of electrodes. The TFT is connected to one of the pair of electrodes. When a voltage is applied across the pair of electrodes, the light emitting layer emits light, and thus an image is displayed.
Moreover, with respect to an organic EL display device such as that described above, a proposal has been made to prevent deterioration of an organic EL element that is caused by moisture or oxygen by providing a sealing film on the organic EL element and sealing the organic EL element with the sealing film.
Moreover, with respect to a conventional organic EL display device such as that described above, as disclosed in Patent Document 1 below, for example, a proposal has been made to provide a sealing film on an organic EL element, the sealing film being constituted by an organic film and an inorganic film that are alternately laminated. It has been considered that deterioration of the organic EL element of this conventional organic EL display device due to moisture or oxygen can be prevented by the sealing film.